It also gives those in California a chance to own one (without the shady dealings with getting a 'used' one previously purchased by a LEO, for IIRC 3x the market price outside Cali.)
It is not made by Polymer80. I looked at attempting one of their builds, but cutting those rails seemed to be daunting. The video makes it seem to be doable for those of us with modest skills and tools.
I know a lot of folks on here are big G43 fans, hopefully one will give it a shot and pass on a honest unbiased report.